This Bioengineering Research Grant proposal addresses the development of analytical and computational methodologies to model and analyze light scattering signals, which can be measured non-invasively from living cells and tissues. Light scattering plays a fundamental role in light trainsport in turbid media such as biological tissues and can provide valuable diagnostic information about the structure and composition of a tissue. Therefore, understanding tissue light scattering will help advance many modalities of optical imaging and diagnostics. However, the mechanisms of light scattering in cells and tissues are still poorly understood. We propose to develop novel analytical and numerical methods to analyze light scattering signals and identify the origins of tissue light scattering utilizing our robust computational finite-difference time-domain (FDTD) and pseudo-spectral time-domain (PSTD) modeling and our novel analytical methods. These studies will be built upon our recent development of analytical and numerical methods to describe spectral and angular properties of light scattering by inhomogeneous and non-spherical particles. The theoretical and computational studies will be accompanied by comprehensive experimental measurements of light scattering in living cells using our recently developed light scattering instrument, which provides multi-dimensional data about the light scattering.